JP2024503429A - Concentrated substance valve and method for operating a concentrated substance valve - Google Patents

Abstract

The present invention is a method for actuating a concentrated substance valve, in which, in a first switching operation, a first volume of hydraulic fluid supplied to a control cylinder (28, 29) causes a valve element (26) to 1 switching state (A) and a second switching state (B), and in the second switching operation, the valve element is actuated by a second volume of hydraulic fluid supplied to the control cylinder (28, 29). This is for switching between a second switching state (B) and a third switching state (C). A first volume of hydraulic fluid is supplied to the control cylinder (28, 29) by a metering piston of a metering cylinder (33, 34, 35) that is displaced from a first end position to a second end position. A second volume of hydraulic fluid is supplied to the control cylinder (28, 29) by a metering piston of the metering cylinder (33, 34, 35) which has been displaced from a first end position to a second end position. The invention also relates to a valve (25) for handling concentrated substances. [Selection diagram] Figure 2

Description

The present invention relates to a concentrated substance valve and a method for operating a concentrated substance valve. The concentrated substance valve includes a valve member switchable between a first switching state, a second switching state and a third switching state.

The actuation of such a concentrated substance valve is very difficult since, on the one hand, high forces have to be applied to actuate the concentrated substance valve and, on the other hand, only a short time of less than 1 second is available for the switching operation. It's not simple. It is possible to meet one of the two conditions, namely high switching forces or short switching times, in a manner known from the prior art. It turns out that implementing a combination of both conditions is not very simple. This is because the end position of the control cylinder cannot be used as a stop, in contrast to concentrated substance valves which only have two positions.

overview

SUMMARY OF THE INVENTION It is an object of the present invention to provide a concentrated substance valve and method that allows a concentrated substance valve to be switched quickly and reliably between a plurality of switching states. This objective is achieved by the features of the independent claims. Advantageous exemplary embodiments are described in the claims.

In the method of the invention, the valve member is switched between a first switching state and a second switching state by a first volume of actuating fluid supplied to the control cylinder. The valve member is switched between a second switching state and a third mp switching state by a second volume of hydraulic fluid supplied to the control cylinder. A first volume of hydraulic fluid is supplied to the control cylinder by a metering piston of the metering cylinder that is displaced from a first end position to a second end position. A second volume of hydraulic fluid is supplied to the control cylinder by a metering piston of the metering cylinder that is displaced from a first end position to a second end position. The second volume of hydraulic fluid may be different from the first volume of hydraulic fluid. Exemplary embodiments in which the valve member is switched between more than three switching states are also included in the invention.

To activate the switching operation, in the method according to the invention, only a single actuating member of the metering cylinder is activated in order to activate the movement of the metering piston within the metering cylinder. The metering cylinder is then moved between the first and second end positions to supply the entire volume of hydraulic fluid to the control cylinder in order to move the valve member to the next switching state. Ru. The metering cylinder, which supplies a defined amount of hydraulic fluid, directly creates the defined state of the control cylinder. In order to control the metering cylinder in dependence on the measurement results, no feedback measuring the state of the control cylinder is required. There is also no need to monitor the state of the metering cylinder or to actuate the second actuating member of the metering cylinder in order to terminate the switching operation.

The concentrated substance valve may have two through openings with which the valve members cooperate. When the valve member opens the through opening, the concentrated substance can pass through. In the closed state of the through-opening, concentrated substances cannot pass through. It is also possible to create an intermediate state in which the through-opening is partially open, so that a reduced volume of the concentrated substance can pass through compared to the open state. Thereby, it is possible to have three switching states in which only the first through opening is opened in the first switching state and only the second through opening is opened in the other switching states. Also, from the first switching state to the second switching state, from the second switching state to the third switching state, from the third switching state to the second switching state, and from the second switching state to the first switching state. It may be configured to be switched to a switching state. This switching sequence can be repeated periodically.

Also, if the concentrated substance valve includes a switching operation that moves the valve member in opposite directions, a separate control cylinder may be provided for each direction of movement. A single control cylinder controlling both directions of movement is also possible.

During the switching operation associated with the invention, a defined amount of hydraulic fluid is conveyed from the metering cylinder to the control cylinder. A control piston disposed within the control cylinder is driven to move the valve member from a first switching position to a second switching position, thereby measuring the volume of hydraulic fluid. The method can be implemented to stop the valve member at the beginning and end of the switching operation. A direct transition between a first switching operation and a subsequent second switching operation is also possible, so that the valve member can reach the end of the first switching operation without being brought to a complete standstill. and is then accelerated again at the beginning of the next switching operation.

The end position of the metering piston is determined by the configuration of the metering cylinder. The end position, in other words, is not from the actuating member of the metering cylinder which is actuated at a particular time to interrupt the flow of hydraulic fluid. The end position may, for example, be defined by mechanical impact of the piston against an element of the metering cylinder. It is also conceivable to surround a volume of hydraulic fluid and thus stop the metering piston when the end position is reached. The end position of the metering cylinder can be a predetermined fixed position. It is also possible for one or more end positions to be changeable, the intervention for changing the end position being carried out at time intervals from the end of the switching operation.

It is possible to associate each valve member switching operation with an individual metering cylinder. In the example described above with three switching states and four switching operations between switching states, there are four metering cylinders, the volume of each metering cylinder corresponding exactly to one of the switching operations. The volume of hydraulic fluid provided to the metering cylinder may vary. If the concentrated substance valve according to the invention is composed of several metering cylinders, they can be in the form of mutually independent units. It is also possible to use a hydraulic block in which several metering cylinders are formed.

A single metering cylinder can be provided that is configured to drive different switching operations of the concentrate valve. The volumes of hydraulic fluid required for both switching operations can be matched. Between the two switching operations driven by this metering cylinder, there may be further switching operations driven by another metering cylinder.

The metering cylinder in the present invention may be configured such that only one direction of movement of the piston is used to drive the control cylinder, and the piston is returned to the starting position before the next switching operation. It is also possible to configure the control cylinder to be controlled using both directions of movement of the piston. In this case, the volumes of hydraulic fluid conveyed in the two directions of movement may be different, as for example in the case of differential cylinders.

In the simplest case, the metering cylinder is configured such that movement between a first end position and a second end position provides exactly one specific volume of hydraulic fluid. Alternatively, the metering cylinder may be configured to provide a first volume of hydraulic fluid and a different second volume of hydraulic fluid. The metering cylinder can have a first metering piston and a second metering piston. The first metering piston and the second metering piston may be connected to each other by a piston rod. Each stroke of the metering cylinder allows both the first metering piston and the second metering piton to displace a defined volume of hydraulic fluid. The metering cylinder can be configured such that the amount of hydraulic fluid supplied does not differ depending on the direction of movement of the piston, in other words, the first volume and the second volume are supplied for each stroke, regardless of the direction of movement. It can be configured such that both are supplied. By using such a metering cylinder, the control cylinder can be controlled with different amounts of hydraulic fluid depending on the switching operation.

In one exemplary embodiment, both metering pistons of the metering cylinder have corresponding cross sections. The difference between the first volume and the second volume may result from the fact that the piston rod is located in only one of the two metering chambers. Which of the two metering pistons carries a larger volume may depend on the direction of movement of the piston.

Alternatively, it is also conceivable for the metering cylinder to have a plurality of metering pistons, the metering pistons having mutually different cross sections. In particular, the metering cylinder can have three metering pistons, two of which have the same cross section and the third a different cross section. In such a metering cylinder it is also possible to provide two different amounts of hydraulic fluid per stroke.

This type of metering cylinder can be used to control two different switching operations of the valve member. A first switching operation may provide a first volume of hydraulic fluid to the control cylinder, and a second switching action may provide a second volume of hydraulic fluid to the control cylinder. It is also possible to use such a metering cylinder to control three different switching operations of the valve member. In addition to the two switching operations mentioned above, a third switching operation can be controlled by the sum of the first volume and the second volume supplied to the control cylinder.

During the switching operation from the first end position to the second end position, when the metering piston of the metering cylinder moves, the control piston of the control cylinder is first accelerated and then braked again. During braking of the control piston, a vacuum is created in the hydraulic fluid within the control cylinder. If the hydraulic fluid withstands the reduced pressure, the working cylinder is sufficiently damped in this way alone. In that case, no additional measures are required to brake the control cylinder.

If too much vacuum is applied to the hydraulic fluid, cavitation may occur and bubbles may form in the hydraulic fluid. As a result, the actuating cylinder may not be braked precisely at the desired position. To prevent this, in addition to the pressure reduction between the control piston and the metering cylinder, it may be provided that the control cylinder is actively braked when the switching position is approached.

The movement by which the valve member is switched between the various switching states may be a pivoting movement. The pivot angle for the transition between the first switching state and the second switching state may be between 10° and 30°, preferably between 15° and 25°. The torque applied to the switching operation may be greater than 1 kNm, preferably greater than 5 kNm, more preferably greater than 10 kNm. In one exemplary embodiment, the applied torque is between 18 kNm and 35 kNm. Higher values, for example up to 100 kNm, are also possible. The switching time for performing the switching operation may be less than 1 second, preferably less than 0.5 seconds, more preferably less than 0.3 seconds. This can be applied to all or part of the switching operation of the concentrated substance valve. In one exemplary embodiment, the switching time is between 0.1 seconds and 0.3 seconds. Note that the time from the end of one switching operation to the start of the next switching operation may be less than 1 second. These values can be applied to some or all of the concentrated substance valve switching operations.

The concentrated substance valve of the present invention can be used to control the flow of concentrated substances in a concentrated substance pump that alternately conveys concentrated substances with two conveying cylinders. The operating cycle of the concentrated substance pump may comprise a first part, in which the first conveying cylinder delivers the concentrated substance in a forward motion through the open first through opening of the concentrated substance valve. The second conveying cylinder withdraws the concentrated substance from the reservoir in a backward movement. In the second part of the operating cycle, the first conveying cylinder, while moving forward, can further convey the concentrated substance through the opened first through opening, while the second through opening is closed such that the dense material in the second transport cylinder is compressible. In the third phase of the operating cycle, the first and second through openings are opened so that the first and second conveying cylinders transport the concentrated substance in parallel into the concentrated substance valve. It may also be possible to transport it. In the fourth phase of the operating cycle, the second conveying cylinder conveys the concentrated substance in a forward movement through the open second through opening of the concentrated substance valve, while the first through opening When released, the first transport cylinder can withdraw the concentrated substance from the reservoir in a backward movement. In a fifth stage, the dense substance is compressed in a second conveying cylinder, and in a sixth stage, the first conveying cylinder and the second conveying cylinder open the first through opening and the second through opening. The operating cycle continues by conveying the concentrated material in parallel through the pump. The operating cycle then begins again.

In one exemplary embodiment particularly suitable for such concentrated substance pumps, the valve member has five switching states. In the first switching state, the first through opening is open and the second through opening is open towards the concentrate storage. In the second switching state, the first through opening is open and the second through opening is closed. In the third switching state, both the first through opening and the second through opening are open. In the fourth switching state, the second through opening is open and the first through opening is open towards the concentrate storage. In the fifth switching state, the second through opening is open and the first through opening is closed.

Further, the volume of hydraulic fluid required for switching from the first switching state to the second switching state is the same as the volume of hydraulic fluid required for switching from the fourth switching state to the fifth switching state. It may be configured so that The concentrated substance valve may comprise a metering cylinder which is actuated both for the transition from the first switching state to the second switching state and for the transition from the fourth switching state to the fifth switching state.

Further, the volume of hydraulic fluid required for switching from the second switching state to the third switching state is the same as the volume of hydraulic fluid required for switching from the fifth switching state to the third switching state. It may be configured so that The concentrated substance valve may comprise a metering cylinder which is actuated both for the transition from the second switching state to the third switching state and for the transition from the fifth switching state to the third switching state. The volume conveyed by the second metering cylinder may be larger than the volume conveyed by the first metering cylinder. The force required to transition from the first switching state to the second switching state may be greater than the force required to transition from the second switching state to the third switching state.

Further, the volume of hydraulic fluid required for switching from the third switching state to the fourth switching state is the same as the volume of hydraulic fluid required for switching from the third switching state to the first switching state. It may be configured so that The concentrated substance valve may comprise a metering cylinder which is actuated both for the transition from the third switching state to the fourth switching state and for the transition from the third switching state to the first switching state. The volume conveyed for this switching operation (third switching operation) is larger than the volume conveyed for the transition from the first switching state to the second switching state (first switching operation). and/or may be larger than the volume conveyed for the transition from the second switching state to the third switching state (second switching operation).

In one exemplary embodiment, the volume of the third switching operation corresponds to the sum of the volume of the first switching operation and the volume of the second switching operation. The third switching operation may be driven with the same metering cylinder/metering cylinder as the first switching operation and the second switching operation.

In one variant, the concentrate valve according to the invention is used to control a pipe switch separate from the concentrate pump. The valve member may be configured such that the first and second inlet openings of the concentrate valve alternately open and close. The pipe switch may have one or more through openings through which the concentrated substance is discharged again from the concentrated substance valve. In the case of multiple through openings, the pipe switch may include a second valve member such that the first through opening and the second through opening are selectively opened and closed. The second valve member may be controlled by the method of the invention. It is also possible for the pipe switch to have two through-openings and it is also possible for the valve member in the context of the invention to be used to switch between the first and second through-openings. be.

The invention further relates to a concentrated substance valve having a valve member switchable between a first switching state, a second switching state and a third switching state. The concentrated substance valve includes a control cylinder for actuating a valve member and one or more metering cylinders having a first end position and a second end position of a metering piston. A first volume of hydraulic pressure is applied by a metering piston that is displaced between a first end position and a second end position to switch the valve member between a first switching state and a second switching state. Fluid is supplied to the control cylinder. A second volume of hydraulic pressure is applied by a metering piston that is displaced between a first end position and a second end position to switch the valve member between a second switching state and a third switching state. Fluid is supplied to the control cylinder.

The invention also relates to a concentrated substance pump comprising a concentrated substance valve according to the invention. A concentrated substance pump may include two or more transport cylinders. Finally, the invention relates to a pipe switch with an agricultural material valve according to the invention.

Thick-walled valves can be developed using the additional features described in connection with the method according to the invention. This method can be developed using additional features described in connection with the concentrated substance valve of the present invention.

The invention will be explained by way of example below with reference to the accompanying drawings and advantageous exemplary embodiments.
FIG. 1 shows a vehicle equipped with a concentrated substance pump according to the invention. FIG. 2 shows a schematic diagram of a concentrated substance pump according to the invention. FIG. 3 shows a functional diagram of the operating cycle of a concentrated substance pump according to the invention. FIG. 4 shows a schematic diagram of a control device for a concentrated substance valve according to the invention. FIG. 5 shows the diagram from FIG. 4 in an alternative exemplary embodiment of the invention. FIG. 6 shows an exemplary embodiment of a metering cylinder for a concentrated substance valve according to the invention. FIG. 7 shows an exemplary embodiment of a metering cylinder for a concentrated substance valve according to the invention. FIG. 8 shows a schematic diagram of a pipe switch according to the invention. FIG. 9 shows a schematic diagram of a pipe switch according to the invention.

detailed description

The truck 14 shown in FIG. 1 is equipped with a concrete pump 5 for conveying liquid concrete from a prefill container 16 via a conveying line 7. The truck 14 shown in FIG. The concrete pump is a dense material pump 15 in the context of the present invention. The conveying line 17 extends along a mast arm 18 that is rotatably supported on a pivot ring 19 . The mast arm 18 comprises three mast arm segments 20, 21, 22 articulated with each other. By pivoting the mast arm segments 20, 21, 22 with respect to each other via the joint, the mast arm 18 can be displaced between a folded state and an unfolded state. The conveying line 17 extends beyond the distal end of the third mast arm segment 22 such that, when the mast arm 18 is collapsed, liquid concrete can be discharged into an area remote from the concrete pump 15. .

As shown in FIG. 2, the concrete pump 15 includes a first conveying cylinder 22 and a second conveying cylinder 23, and these first conveying cylinders 22 and second conveying cylinders 23 are In operation, liquid concrete is sucked out of the prefill container 16 and conveyed in the direction of the through opening 24 . The flow of liquid concrete between the conveying cylinders 22 , 23 and the through opening 24 is controlled by arranging a concentrated substance valve 25 between the conveying cylinders 22 , 23 and the through opening 24 . The concentrated substance valve comprises a valve member 26 which is pivotably supported about a pivot shaft 32 and can be switched between different switching states by means of an actuating lever 27 . The concentrated substance valve 25 comprises a first control cylinder 27 and a second control cylinder 28 which act in a hydraulically driven manner on an actuating lever 27 .

According to FIG. 3, the concentrated substance valve 25 has several switching states that follow one another during the operating cycle of the concrete pump 15 as follows. In switching state A, the control cylinder 28 is fully extended and the actuating lever 27 has been moved counterclockwise to its outermost position. The valve member 26 opens a first through opening 20 that is connected to the interior space of the first conveying cylinder 22 . The first conveying cylinder 22 conveys liquid concrete to the through opening 24 during this phase of the operating cycle while advancing through the first through opening 30 and the interior space of the valve member 26 . The second through opening 31 is open in switching state A, and the second conveying cylinder 23 can withdraw liquid concrete from the prefill container 16 in a backward movement.

Starting from switching state A, the concentrate valve is switched into switching state B by slightly extending the second control cylinder 29. The actuating lever 27 is pivoted in a clockwise direction to a position located between the external position from the switching state A and the center position of the actuating lever 27. The first through opening 30 remains open so that the first conveying cylinder 22 can continue conveying liquid concrete via the valve member 26. The second through opening 31 is closed and the second conveying cylinder 23 compresses the liquid concrete in the second conveying cylinder 23 by a forward movement.

Starting from switching state B, switching to switching state C is effected by further extending the second control cylinder 29 and locating the actuating lever 27 in the central position. The valve element 26 opens a first through opening 30 and a second through opening 31 so that both conveying cylinders 22, 23 can convey liquid concrete in parallel through the valve element 26.

Starting from switching state C, by fully extending the second control cylinder 29 and implementing switching state D, the actuating lever 27 is moved clockwise to its outermost position. The valve element 26 opens a second through opening 31 so that the second conveying cylinder 23 can convey liquid concrete through the valve element 26 . By releasing the first through opening 30, the first conveying cylinder 22 can withdraw liquid concrete from the prefill container 16 with a backward movement.

Starting from switching state D, the concentrated substance valve is switched to switching state E by slightly extending the first control cylinder 28 . The actuating lever 27 is pivoted counterclockwise to a position located between the external position from the switching state D and the central position of the actuating lever 27. The second through opening 31 is open so that the second conveying cylinder 23 can continue conveying liquid concrete via the valve member 26 . The first through opening 30 is closed and the second conveying cylinder 23 compacts the liquid concrete in the first conveying cylinder 22 by a forward movement.

Starting from switching state E, the concentrate valve is switched to switching state F by further extending the first control cylinder 28 and placing the actuating lever 27 in the central position. The valve element 26 opens a first through opening 30 and a second through opening 31 so that both conveying cylinders 22, 23 can convey liquid concrete in parallel via the valve element 26.

Starting from switching state F, the first control cylinder 28 is fully extended to carry out the switching to switching state A. As a result, a new operating cycle of concrete pump 15 begins.

Between switching state A and switching state F there is a pivot angle of approximately 80°. The switching operation between switching state A, switching state B, switching state C and between switching state D, switching state E, switching state F extends in each case over a swivel angle of approximately 20°. The torque that must be applied for the switching operation is approximately 30 kNm. The switching time of the switching operation is approximately 0.3 seconds. The residence time in the switching state before a witching operation before the next operation is less than 1 second.

The control cylinders 28 and 29 are controlled via a plurality of measuring cylinders 33, 34, and 35 configured according to FIG. executed according to the following. During the transition from switching state A to switching state B, the first metering cylinder 33 is displaced from the first end position to the second end position, and a hydraulic pressure with a volume of 440 ml is applied to the second control cylinder 29. Supply fluid. During the transition from switching state B to switching state C, the second metering cylinder 34 is actuated to supply a volume of 530 ml of hydraulic fluid to the second control cylinder 29. During the transition from switching state C to switching state D, the third metering cylinder 35 is actuated to supply the second metering cylinder 29 with a volume of 970 ml of hydraulic fluid. The transition between switching state D, switching state E and switching state F is therefore carried out in the counter-rotational direction by means of the metering cylinders 33, 34, 35 which are driven in the counter-rotational direction.

In each switching operation, exactly one metering cylinder 33, 34, 35 is moved from the first end position to the second end position. This requires in each case actuation of only a single actuating member of the metering cylinders 33, 34, 35, whereby the movement of the respective metering piston is initiated, and the movement of the metering piston is initiated by the movement of the second metering piston. It ends automatically when the end position is reached, without actuating another actuating member or carrying out any other control or regulating operations.

In an alternative exemplary embodiment according to FIG. 5, the control of the control cylinders 28, 29 is carried out using only two metering cylinders 34, 35. For the transition from switching state A to switching state B, the first metering cylinder 33 is actuated again, and for the transition from switching state B to switching state C, the second metering cylinder 34 is actuated. Ru. The transition from switching state C to switching state D is carried out by actuating both the first metering cylinder 34 and the second metering cylinder 35. The sum of the volumes of the two metering cylinders 34, 35 corresponds to the greater pivot angle through which the valve member 26 moves between the switching state C and the switching state D. Transition from switching state D to switching state E by the first metering cylinder 34, transition from switching state E to switching state F by the second metering cylinder 35, and switching from switching state F by the two metering cylinders 34, 35 In the order of transition to state A, a switch in the opposite direction is performed.

The metering cylinders 33, 34, 35 can be separate components, with separate cylinders and pistons arranged inside them. Further, a hydraulic block type configuration in which a plurality of cylinders are formed in the hydraulic block is also possible.

Alternatively, the invention may be implemented by providing multiple metering chambers in a single metering cylinder. In FIG. 6, a metering cylinder 36 of the differential cylinder type is shown. Two pistons 37 , 38 are arranged in the metering cylinder 36 and are connected by a piston rod 39 . A first metering chamber 41 is enclosed between the first location 37 and the opposing front wall 40 . A second metering chamber 43 is enclosed between the second piston 38 and the central wall 42 . When the piston is moved from the rightmost position to the leftmost position shown in FIG. As a result of the piston rod 39 , the volume of the first metering chamber 41 is smaller than that of the first metering chamber 41 . The opposite is true when the piston moves in the opposite direction. The control cylinders 28, 29 are suitably connected to the first metering chamber 41, the second metering chamber 43 or both metering chambers 41, 43 simultaneously, thereby performing all switching operations shown in FIGS. 4 and 5. can be controlled.

Another exemplary embodiment of a metering cylinder 44 suitable for the present invention is shown in FIG. The metering cylinder 44 has three pistons 45, 46, 47, of which the central piston 45 has a large diameter and the two outer pistons 46, 47 have a small diameter. The three pistons 45, 46, 47 are connected to each other by a piston rod 48. At the right end position, the piston 47 abuts against the right front wall 49. At the left end position, the piston 46 abuts the left front wall 50. When the pistons 45, 46, 47 are moved from the rightmost position to the leftmost position, a first volume of hydraulic fluid is displaced from the outer piston 46 and a second volume of hydraulic fluid is displaced from the central piston 45. . This also applies to the reverse movement direction of the pistons 45, 46, 47. 4 and 5 by either the volume displaced by the external pistons 46, 47 or the volume displaced by the central piston 45, or the sum of both volumes being supplied to the control cylinders 28, 29. All switching operations of the concentrated substance valve 25 can be controlled.

According to FIG. 8, the concentrated substance valve according to the invention can also be used in the form of a pipe switch 51 that is not a component of a concrete pump. Pipe switch 51 has two inlet openings 52, 53 and a through opening 54. Piping (not shown) through which liquid concrete is conveyed to the pipe switch 51 is connected to the inlet openings 52 and 53. By switching the concentrated substance valve, either liquid concrete from the first inlet opening 52 or liquid concrete from the second inlet opening 53 or liquid concrete from the two inlet openings 52, 53 can be passed through the opening. 54. According to the invention, it is also possible to use the concentrated substance valve according to the invention in a pipe switch 55 having an inlet opening 56 and two through openings 57, 58.

Claims (12)

1. A method of operating a concentrated substance valve, the method comprising:
The valve member (26) is switched between a first switching state (A) and a second switching state (B) in a first switching operation by means of a first volume of hydraulic fluid supplied to the control cylinders (28, 29). ) and said valve member is switched between the second switching state (B) and the third switching state (B) in a second switching operation by means of a second volume of hydraulic fluid supplied to the control cylinders (28, 29). switching state (C), said first volume of hydraulic fluid is transferred to said controlled state by a metering piston of a metering cylinder (33, 34, 35) displaced from a first end position to a second end position. The second volume of hydraulic fluid is supplied to the cylinder (28, 29) by a metering piston of a metering cylinder (33, 34, 35) being displaced from a first end position to a second end position. A method, in which the control cylinders (28, 29) are supplied. Claim 1, characterized in that the first switching operation is actuated using a first metering cylinder (33) and the second switching operation is actuated using a second metering cylinder (34). The method described in 1. The valve member (26) is switched between a third switching state (C) and a fourth switching state (D) using a third switching operation, and the hydraulic fluid in the third switching operation is switched between a third switching state (C) and a fourth switching state (D). 3. Method according to claim 1, characterized in that the volume corresponds to the sum of the volume of the first switching operation and the volume of the second switching operation. 4. The method according to claim 1, wherein a metering cylinder (36, 44) is used to drive the first switching operation and the second switching operation. 5. Method according to claim 4, characterized in that the metering cylinder (36, 44) has a plurality of metering pistons (37, 38). In a first switching operation, said volume of hydraulic fluid conveyed with said first metering piston (37) is supplied to said control cylinder (28, 29), in a second switching operation said 6. Method according to claim 5, characterized in that the volume of hydraulic fluid conveyed using two metering pistons (38) is supplied to the control cylinders (28, 29). In a third switching operation, the sum of the volumes of hydraulic fluid conveyed using the first metering piston (37) and the second metering piston (38) is transferred to the control cylinder (28, 29). 7. The method according to claim 6, characterized in that: 8. The valve member (26) according to claim 1, wherein the valve member (26) is actuated with a pivoting movement, and the pivoting angle for the switching operation is between 10° and 30°. Method. Method according to any one of claims 1 to 8, characterized in that in the switching operation a torque of at least 1 kNm, preferably at least 5 kNm, more preferably at least 10 kNm is applied. Method according to any one of claims 1 to 9, characterized in that the switching time is less than 1 second, preferably less than 0.5 seconds, more preferably less than 0.3 seconds. A valve member (26) switchable between a first switching state (A), a second switching state (B) and a third switching state (C), and a control cylinder (26) for actuating the valve member (26). 28, 29) and one or more metering cylinders (33, 34, 35, 36, 44) having a first end position and a second end position of the metering piston,
for switching the valve member between the first switching state (A) and the second switching state, the control cylinder is actuated by a metering piston displaceable between a first end position and a second end position. A first volume of hydraulic fluid is supplied to the first end position and the second end position for switching the valve member between the second switching state (B) and the third switching state (C). A second volume of hydraulic fluid is supplied to said control cylinder (28, 29) by a lightweight piston that is displaced between positions. A concentrated substance pump having a first conveying cylinder (22), a second conveying cylinder (23) and a concentrated substance valve (25), the pump comprising:
The concentrated substance valve is configured as claimed in claim 11, wherein the first inlet opening (30) of the concentrated substance valve (25) is connected to the first conveying cylinder (22) and Concentrate substance pump, characterized in that the second inlet opening (31) of the substance valve (25) is connected to said second conveying cylinder (23).

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